Development, characterization, and shelf life studies of phytonutrient-rich date bar from immature dates (Pheonix dactylifera L.)

Immature dates with low commercial viability are rich in bioactive compounds and have potential for value addition. The present study aimed at utilizing date paste from immature dates to develop a natural and high antioxidant fruit snack for health food markets. Pectin was added at different concentrations (1-4%) to improve the quality of formulated date bars. Increasing the pectin levels increased the hardness of formulated bars while decreased moisture content and water activity, without affecting color and nutritional properties. Developed bars showed high mineral content and phytochemical constituents as confirmed using Fourier transform-infrared (FTIR) analysis. The microstructure of date bars was consistent with the texture values. Based on desirable sensory and textural properties, date bars formulated with addition of 4% pectin was selected for product development and evaluation of shelf life under room (25 +/- 2 degrees C) and refrigerated (4 +/- 2 degrees C) conditions. Significant (p < 0.05) variation was noticed in moisture content of formulated date bar during storage at both temperatures. Total and reducing sugars and bioactive constituents decreased, while water activity, titarable acidity, hardness of texture, and yeast and mould count increased significantly with advancement of storage period, irrespective of storage temperatures. Except moisture, the extent of quality changes was rapid at room temperature. Developed product showed high organoleptic acceptability as well as microbial safety up to 30 days at room temperature and 50 days under refrigeration. Valorization of immature dates can provide dual benefit of producing healthy phytonutrient-rich snack product along with date waste management.

Automated summary

This study aimed to develop a natural and high antioxidant fruit snack using date paste from immature dates. Pectin was added to improve the quality of formulated date bars, and the bars with 4% pectin were selected for product development and shelf life evaluation. The results showed that the developed bars had high mineral content and phytochemical constituents, and they were organoleptically acceptable and microbiologically safe for up to 30 days at room temperature and 50 days under refrigeration.